relative humidity

noun

: the ratio of the amount of water vapor actually present in the air to the greatest amount possible at the same temperature

Examples of relative humidity in a Sentence

Recent Examples on the Web
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There is plenty of dry fuel to burn across the ground across interior California, and afternoon relative humidity values could drop as low as 15% to 20% in portions of the Central Valley. Sean MacAday, Sacbee.com, 2 July 2026 Instead of just looking at temperature when planning outdoor activities, check the heat index, which accounts for heat illness risk associated with temperature and relative humidity. Brian Bossak, The Conversation, 1 July 2026 Wind gusts of up to 40 mph are forecast across the fire-danger zones, and relative humidity is expected to fall between 8% and 15%, meaning conditions are ripe for any new fires to rapidly spread. Bill Hutchinson, ABC News, 30 June 2026 The heat index combines atmospheric temperature and relative humidity to determine how heat feels to the body. Adriana Pérez, Chicago Tribune, 29 June 2026 See All Example Sentences for relative humidity

Word History

First Known Use

1819, in the meaning defined above

Time Traveler
The first known use of relative humidity was in 1819

Browse Nearby Words

Cite this Entry

“Relative humidity.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/relative%20humidity. Accessed 5 Jul. 2026.

Kids Definition

relative humidity

noun
: the amount of water vapor actually present in the air compared to the greatest amount possible at the same temperature

Medical Definition

relative humidity

noun
: the ratio of the amount of water vapor actually present in the air to the greatest amount possible at the same temperature compare absolute humidity

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